The usual way to remove the silicon layer is used by the solutions of HF and KOH to conduct the etching process, but those chemicals are dangerous for the humans. Therefore, this study proposes the method that uses the diamond millstone to reduce the thickness of the silicon wafer. It hopes that this method can effectively shorten the process time and reduce the amount of chemical pollution. Firstly, the effects of the working pressure, the rotating speed of the wafer, and the diamond millstone on the removing rate of silicon wafer are investigated. Then, the effect of the working pressure on the flatness of the wafer surface is investigated. Finally, the effect of the rotating speed ratio of the wafer to the diamond millstone on the track type of grinding surface is theoretically analyzed. According to the experimental results, the removing rate of silicon wafer is almost linearly proportional to the working pressure, the rotating speed of the wafer, and the diamond millstone. The lighter working pressure, the more flatness of the wafer is. According to the theoretical results, the rotating speed ratio of the wafer to the diamond millstone influences the track type of grinding surface. When this rotating speed ratio is an irrational number, the distribution of grinding track becomes finer.

No description available.

In conventional abrasive machining , it must using dresser to dress the surface of polishing disc periodically , in order for polishing disc to maintain its ability of machining , and then ensuring the quality of work piece. It will make polishing disk thin , finally it must losing it ability of machining , and then be replaced by a new disc. For this reason , in the study , an idea of a new type ultraprecision polisher is proposed . Using Sn-Al2O3 composite coating to reach the mirror surface grinding of silicon wafer in the tin bath , and grinding with electroplating continuously . It will ensure the ability of machining of polishing disc . In the study , first , analyzing the effect of rotational speed rate of wafer and polishing disc on the grinding trajectories type of machining surface . From the result of analysis , find that , when the rotational speed rate is more irregular or it could not divided , the arrangement of grinding trajectories is more complex . And then , investigating the effect of cathode current density , rotational speed of polishing disc and time of plating on the characteristics of composite coating . In the experiment of composite electroplating , when cathode current density is higher , the size of crystal is smaller , the thickness of coating is thicker , and the quantity of Al2O3 within coating decrease lightly . The increase of the rotational speed of polishing disk could increase the size of crystal , the thickness of coating and the quantity of Al2O3 lightly . The time of plating is longer , the shape of crystal is more obvious , the thickness of coating is thicker and it also increase the quantity of Al2O3 . Finally , investigating the effect of cathode current density and cationic surfactant PEI on the characteristics of coating and wafer . In practical abrasive machining , the removal rate of wafer increases with cathode current density , and the addition of PEI could increase the quantity of Al2O3 indeed . Besides , under the same machining condition , in the tin bath with PEI , the removal rate is higher than the one in the tin bath without PEI .

In the study, the effects of the machining conditions, ex, machining positions, loads and rotating speed ratio on machining mechanism of wafer are investigated by using the continuous composite electroplated polisher and find the best machining conditions of the polisher. Experimental results show that when the wafer and polisher are full contact, the operating of machinery is most smooth and the flatness is better. When the load is increased, the reducing rate of average roughness¡]Ra¡^and maximum roughness¡]Rmax¡^, removal rate, and the speed of mirror degree are increased. The machining mechanism and the stability of machinery is depended on the value of rotating speed ratio. In the different rotating speed ratio, the flatness of wafer is difference. For example, the rotating speed ratio is 1, the flatness is 1.5 £gm/38 mm. The rotating speed ratio is 2, the flatness is 2.3 £gm/38 mm. Finally, choose the rotating speed ratio, which the values of rotating speed are close and complex on the range of rotating speed which machinery can be operating most stable in machining process. Because of the machining mechanism are similar and the grinding locus are finer. Hence, the flatness of wafer becomes better. When the rotating speed ratio is 1.1, the flatness is 1.46£gm/38 mm. The rotating speed ratio is 1.11, the flatness is 1.45£gm/38 mm. The effect of the rotating speed ratio of the wafer and polisher on the grinding locus type of grinding surface is theoretically analyzed. Results show that when the rotating speed ratio is irregular, the distribution of grinding locus becomes finer. The analyzable results of locus and provable results of experiment are the same.

In this dissertation, three types of microfabricated solid-state sensors had been designed and developed on silicon wafers, aiming to detect hydrogen gas at elevated temperatures. Based on the material properties and sensing mechanisms, they were operated at 140°C, 500°C, and 300°C. The MOS-capacitor device working at 140°C utilized nickel instead of the widely-used expensive palladium, and the performance remained excellent. For very-high temperature sensing (500°C), the conductivity of the thermally oxidized TiO2 thin film based on the anodic aluminum oxide (AAO) substrate changed 25 times in response to 5 ppm H2 and the response transient times were just a few seconds. For medium-high temperatures (~300°C), very high sensitivity (over 100 times’ increment of current for H2 concentration at 10 ppm) was obtained through the reversible reduction of the Schottky barrier height between the Pt electrodes and the SnO2 nano-clusters. Fabrication approaches of these devices included standard silicon wafer processing, thin film deposition, and photolithography. Materials characterization methods, such as scanning electron microscopy (SEM), atomic force microscopy (AFM), surface profilometry, ellipsometry, and X-ray diffractometry (XRD), were involved in order to investigate the fabricated nano-sized structures. Selectivities of the sensors to gases other than H2 (CO and CH4) were also studied. The first chapter reviews and evaluates the detection methodologies and sensing materials in the current research area of H2 sensors and the devices presented this Ph.D. research were designed with regard to the evaluations.

The goal of this research was to investigate an experimental infrared transmission technique to extract the full stress components of the in-plane residual stresses in thin multi crystalline silicon wafer, and try to meet the need of photovoltaic industry to in situ measure residual stress for large cast wafers.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22442号 / 工博第4703号 / 新制||工||1734(附属図書館) / 京都大学大学院工学研究科原子核工学専攻 / (主査)教授 斉藤 学, 教授 神野 郁夫, 准教授 松尾 二郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Neste trabalho foi estudado o desenvolvimento de uma superfície modelo de silício monocristalino, SiO2/Si, modificada com organossilanos derivados de N-heterocíclicos que permitisse a imobilização de um complexo de coordenação, FeTIM. Estas superfícies modificadas poderão ser empregadas em estudos de reatividade frente a analitos de interesse, como o NO. Sob esse aspecto, a síntese desses novos silanos, contendo N-heterocíclicos, e o desenvolvimento de uma metodologia de formação dos filmes finos automontados, sobre a superfície de SiO2/Si, tornou-se de grande relevância na aplicabilidade deste trabalho. Para a obtenção dessas superfícies, fez-se necessária a compreensão dos parâmetros de formação dos filmes de silanos. Os parâmetros estudados foram os efeitos do tempo de adsorção, da concentração da solução dos silanos, da polaridade do solvente e do tamanho da cadeia alquílica do silano no processo de formação dos filmes. Deste modo, foi possível inferir sobre as alterações na morfologia e na estrutura química dos filmes formados, através de medidas de Espectroscopia de Fotoelétrons excitados por Raios-X (XPS), Microscopia de Força Atômica (AFM) e Microscopia Eletrônica de Varredura (MEV). A imobilização do complexo de FeTIM sobre a superfície organomodificada foi comprovada pela variação da linha de fotoemissão do Fe 2p nas medidas de XPS. / This work describes the study of model surfaces on oxidized silicon wafer, SiO2/Si, modified with N-heterocycles rings, that allows the grafting of a macrocycle iron complex, FeTIM, that could be used in reactivity studies, with biologically relevant molecules, as nitrogen monoxide (NO). On this way, the synthesis of these silanes and a new methodology of the formation of self-assembled monolayers had become a relevant question on this work applicability. These thin films contain silanes bearing nitrogenated Lewis bases on silicon surfaces. In order to obtain these modified surfaces, it was necessary a comprehensive study of the adsorption parameters of the thin films. The parameters studied were the effect of: adsorption time, the solution concentration, the role of the solvents polarity and the chain length alkylsilanes in the film formation. Then, it was possible to infer about the film\'s morphology differences and chemical structures by the XPS, AFM and MEV measurements. X-ray photoemission lines of Fe 2p were used to probe the iron chemical environment in the chemically adsorbed macrocycles complexes.

Neste trabalho foi estudado o desenvolvimento de uma superfície modelo de silício monocristalino, SiO2/Si, modificada com organossilanos derivados de N-heterocíclicos que permitisse a imobilização de um complexo de coordenação, FeTIM. Estas superfícies modificadas poderão ser empregadas em estudos de reatividade frente a analitos de interesse, como o NO. Sob esse aspecto, a síntese desses novos silanos, contendo N-heterocíclicos, e o desenvolvimento de uma metodologia de formação dos filmes finos automontados, sobre a superfície de SiO2/Si, tornou-se de grande relevância na aplicabilidade deste trabalho. Para a obtenção dessas superfícies, fez-se necessária a compreensão dos parâmetros de formação dos filmes de silanos. Os parâmetros estudados foram os efeitos do tempo de adsorção, da concentração da solução dos silanos, da polaridade do solvente e do tamanho da cadeia alquílica do silano no processo de formação dos filmes. Deste modo, foi possível inferir sobre as alterações na morfologia e na estrutura química dos filmes formados, através de medidas de Espectroscopia de Fotoelétrons excitados por Raios-X (XPS), Microscopia de Força Atômica (AFM) e Microscopia Eletrônica de Varredura (MEV). A imobilização do complexo de FeTIM sobre a superfície organomodificada foi comprovada pela variação da linha de fotoemissão do Fe 2p nas medidas de XPS. / This work describes the study of model surfaces on oxidized silicon wafer, SiO2/Si, modified with N-heterocycles rings, that allows the grafting of a macrocycle iron complex, FeTIM, that could be used in reactivity studies, with biologically relevant molecules, as nitrogen monoxide (NO). On this way, the synthesis of these silanes and a new methodology of the formation of self-assembled monolayers had become a relevant question on this work applicability. These thin films contain silanes bearing nitrogenated Lewis bases on silicon surfaces. In order to obtain these modified surfaces, it was necessary a comprehensive study of the adsorption parameters of the thin films. The parameters studied were the effect of: adsorption time, the solution concentration, the role of the solvents polarity and the chain length alkylsilanes in the film formation. Then, it was possible to infer about the film\'s morphology differences and chemical structures by the XPS, AFM and MEV measurements. X-ray photoemission lines of Fe 2p were used to probe the iron chemical environment in the chemically adsorbed macrocycles complexes.

Bacterial adhesion is the first step of biofilm formation and in the focus of research interest since several decades. Biofilms cause many problems, sometimes dramatic, for example in health, food packing or waste water purification. Despite of high interest, bacterial adhesion process is only poorly understood yet. In this work, bacterial adhesion was investigated on well-organized and structured model surfaces with various chemistries at molecular scale. For that purpose a characterization methodology was developed to sufficiently analyze monolayers on silicon wafers, and controlled mixed monolayers surfaces with different densities of NH 2 backfilled with CH3 were developed and optimized. These controlled surfaces with different densities of 0 % NH2 up to 100% NH2 were eventually used as tool to study bacterial adhesion in batch and real time conditions. The results demonstrate a significant impact on bacterial adhesion of weak difference in the surface chemistry at molecular scale. In the batch experiments, two so-called "plateaus" zones were determined, in which bacterial adhesion is not significantly different despite the change of the amine concentration on the surface. On the contrary, one transition zone exists between the "plateaus" in which a slight chunge.in the amine concentration leads to a significant increase / decrease of the bacterial adhesion. The same trend of bacteria behavior was observed for different bacterial strains.